This country's response to the president on Iran, nuclear-bound and said to be meddling in Iraq, should be crafted around two words: shouldn't and can't.

The United States shouldn't jump into any other military adventure on Iran's account for a host of reasons. Key among them is because diplomacy spills no blood and hasn't been given ample opportunity.

But also because this country simply can't. It is stretched too thin in Iraq to do anything substantive militarily.

But there is one thing about this Iran debate that positively puzzles. That is the incredulity in the administration that anyone would doubt its claims about Iran and about what it intends to do about them.

It is as if the administration believes the public has been asleep since 2003 and during the walk-up to the war in Iraq. The nation doubts because it has discovered, to its dismay and misfortune, that it has no other choice.

Defense Secretary Robert Gates said recently, "I don't know how many times the president, secretary (of state Condoleezza) Rice and I have had to repeat that we have no intention of attacking Iran."

Hmm. And still the doubts.

Everything the administration says about Iran might be true, but anyone blaming the doubters has been inattentive since the first administration official uttered those fateful words: weapons of mass destruction, Sept. 11 and al-Qaida links to Saddam Hussein, mobile labs and mushroom clouds.

There can now be little doubt that this administration was more intent on going to war in Iraq than on legitimately proving a war of choice was necessary. Manipulation is a harsh word, but it appears to fit.

There is much to lament about what we've lost in the Iraq war. But, sadly, credibility and trust might be among the most grievous casualties.